Method and device for controlling a uniform fleece supply during tufting

ABSTRACT

A method and apparatus for the production of fleece like fabrics in which fleece material is delivered to a storage unit from which it is withdrawn by a tufting machine. To ensure constant delivery to the machine the rates of delivery to and withdrawal from the storage unit are compared and one of the rates controlled as need be so that the rates are equal. To effect the control there is provided a differential to which two inputs are applied, one being proportional to the delivery rate and the other to the withdrawal rate. When the inputs are equal the differential cage is stationary but when they are different the cage is rotated and that movement used to control one of the rates.

United States Patent [191 Grenzendorfer et al.

[4 Oct. 21, 1975 I-Ientschel, both of Karl Marx Stadt, Germany [73] Assignee: VEB Wirkmaschinenbau Karl-Marx-Stadt, Karl-Marx-Stadt, Germany 22 Filed: Jan. 18, 1973 21 Appl. No.: 324,621

[56] References Cited UNITED STATES PATENTS 3/1960 Nelson 19/163 2/ 1963 3,078,023 Hecker 226/118 3,097,413 7/1963 Draper 28/722 R 3,395,065 7/1968 Owen 3,550,543 12/1970 Crawford 112/79 Primary ExaminerLouis K. Rimrodt Attorney, Agent, or FirmNolte and Nolte [57] ABSTRACT A method and apparatus for the production of fleece like fabrics in which fleece material is delivered to a storage unit from which it is withdrawn by a tufting machine. To ensure constant delivery to the machine the rates of delivery to and withdrawal from the storage unit are compared and one of the rates controlled as need be so that the rates are equal. To effect the control there is provided a differential to which two inputs are applied, one being proportional to the delivery rate and the other to the withdrawal rate. When the inputs are equal the differential cage is stationary but when they are different the cage is rotated and that movement used to control one of the rates.

7 Claims, 3 Drawing Figures U.S. Patent Oct. 21, 1975 Sheet 1 of 3 3,913,504

US. Patent Oct. 21,1975 Sheet20f3 3,913,504

FIG. 2

U.S. Patent 0a. 21, 1975 Sheet 3 of3 V w w METHOD AND DEVICE FOR CONTROLLING A UNIFORM FLEECE SUPPLY DURING TUFTING The invention concerns a method and a device for the continuous production of a textile fabric from a fleece-like preparatory material where the arrangement consists of a fleece former (such as a card and lapping machine), a storage unit to which the fleece is delivered and a machine which withdraws the fleece from the storage unit and processes it such as a tufting mechanism. In such continuous production it is necessary that the rate of delivery of the fleece to the storage unit be equal to the rate of withdrawal so that the finished fabric should be uniform.

An arrangement for the continuous production of a textile fabric from the fleece-like preparatory material is already known in which, to ensure a uniform web, a box feeder and the feeding device as well as takeoff of the lapping machine are stopped at the same time as the tufting mechanism provided with an instant stop while the takeoff of the fine pile former is only stopped after its cylinder has delivered to the takeoff the fibers which it received from the tufting mechanism before the stoppage.

To this end the takeoff of the fine pile former is provided with a separate drive which drives the takeoff, after the tufting mechanism has stopped, at a speed which is substantially lower than its normal speed.

With this control, thick places are formed in the textile fabric which are caused by the stripping of the material on the cylinder to the takeoff when the tufting mechanism is stopped. These thick places are so pronounced in light weight, highgrade textile fabrics, that the application of this control principle is no longer possible for such fabrics.

Another known arrangement of this type has a compensator arranged between the lapping machine and the tufting mechanism which corrects the discrepancies caused by the different inlet and outlet conditions of the lapping macnine and tufting mechanism by arranging a movable third feeder between two stationary fleece feeders in such a way that it stores'and releases the fleece in a loop (catenary) during its movement. The movement of this feeder is controlled by a chain which is driven on one side by the lapping machine and on the other side by the tufting mechanism. The movable feeder controls in its movement the working speed of the lapping machine and of the tufting mechanism.

This bulky, complicated and very expensive design of this arrangement permits its use only for small or medium size working widths of the tufting mechanism.

Furthermore, continuous machines are known where the continuity is ensured by the fact that the web sags in a loop (catenary) between the lapping machine and the tufting mechanism and that the necessary control measures are started by photocells in dependence on the extent of the sag.

The disadvantages of these arrangements are that false drafts appear in the sagging fleece and that the storage capacity is low.

The object of the invention is to eliminate the disadvantages of the above described arrangement and to provide a possibility of producing high-quality textile fabrics from a fleece-like preparation material in great, economically feasible working widths.

The invention is based on the problem of providing a method and a device which permit to obtain an exact positive synchronism between the fleece forming and fleece processing parts of the machine, where the control of processing machines of any width can be effected by the same control device and where a space saving, simple to produce and cost saving control device is used.

This problem is solved according to the invention in this way that a storage unit is provided between the lapping machine and the tufting mechanism, into which the fleece arriving from the lapping machine is deposited and from which the fleece required by the tufting mechanism is withdrawn, the rate of feed and the rate of withdrawal of the fleece being compared automatically by a stationary and position-independent control device. It is possible for the control device to be stationary and position independent since its inputs are derived by means of flexible shafts, which enable the device to be physically mounted to the tufting mechanism or to the lapping machine or to any other convenient mounting place. The measures necessary for the control of the continuous arrangement are derived from the difference between the rate of speed at which the tufting mechanism is operated to withdraw fleece from the storage unit and the rate of speed at which fleece is delivered to the storage unit. Thus, in synchronizing the delivery and withdrawal rates of the fleece to and from the storage unit, by controlling the rate of speed of either the tufting mechanism or the delivery rate, it is possible to maintain a desired level of fleece in the storage trough 5. As a control device is used preferably differential gears which have two drives and where the difference can be made visible over a separate driving element.

The control device according to the invention has the effect that, when the tufting mechanism is stopped, the lapping machine continues to run at a reduced speed. The driven element of the differential gear changes its starting position in such a way that the entire arrangement is stopped over control impulses when the tufting mechanism stops for a prolonged period, in order to avoid major accumulations of fleece in front of the tufting mechanism.

Furthermore, irregularities can occur in the course of the normal operation of the continuous machine, due to irregular balancing of the individual units, which can manifest themselves as defects in the finished textile fabric. By means of the control device speed differences of the various units can be corrected and adapted to each other.

The invention will now be described more fully on the basis of the drawings, in which:

FIG. 1 shows the arrangement of the units of a continuous machine for the production of textile fabrics from a fleece-like preparatory material;

FIG. 2 shows a control device with a mechanical differential gear; and

FIG. 3 shows a side elevation of FIG. 2.

The continuous machine according to FIG. 1 consists of the box feeder l, the card 2, the lapping machine 3, the feed cloth 4, the storage trough 5, the tufting mechanism 6, the sewing thread beam 7, the winding device 8 and the control device 9. Box feeder 1, card 2 and lapping machine 3 are combined in known manner to a driving unit. The tufting mechanism 6, sewing thread beam 7, and winding block 8 are likewise combined in known manner to a second unit. From the driving unit, of the lapping machine, originates a flexible shaft 10, positively or frictionally connected with the latter,

which runs to the.control device at a speed proportional to the rate of feed of the fleece. From the driving unit of the tufting mechanism originates likewise a flexible shaft 11 positively or frictionally connected with the latter, which runs to the control device at a speed proportional to the rate of withdrawal of the fleece. Thus, it can be seen, that the embodiment comprises a control device 9 for apparatus for the continuous production of textile material of a fleece-type preparatory material, which compares the rate at which the fleece is delivered to a storage trough 5 and the rate at which the fleece is withdrawn from the storage trough 5 by mechanically connecting, by means of flexible shafts l and 11, the rate at which the feed cloth 4 is operated to deliver fleece to the storage trough S and the rate at which the tufting mechanism 6 is operated to withdraw the fleece from the storage trough 5. In this manner, it is possible to correlate the amount of fleece stored in the storage trough by monitoring the delivery and withdrawal rates of the fleece.

The control device 9 according to FIG. 2 works as follows: the flexible shafts l0 and 11 drive at speeds proportional to the rate of feed and rate of withdrawal of the fleece over the clutches 12, 13 and the shafts 14, 15 to the bevel gears 16, 17. With the same circumferential speed of the gears l6, 17, the bevel gear 18 rotates on the bolt 19 and thelatter maintains its position. If the circumferential speed of one of the two gears l6, 17 is changed for example by briefly disconnecting the tufting mechanism 6, the gear 18 hobs on the slower gear 16 or 17 at a rate related to the difference in angular speeds of gears 16 and 17. The bolt 19, which is rigidly connected with the bar 20, Le. the differential case, moves on a circular path around the axis of rotation of the shaft 14, 15. The gear 21 rigidly connected with the bar or case transmits the rotary movement of the bar 20 to the gear 22. The angle of rotation of the bar 20, which is limited in practice to that corresponding to the maximum capacity of the storage trough 5, is reduced toan angle of rotation of less than 360 degrees. This is necessary to be able to actuate the limit switches 26 without additional auxiliary means or intermediate members, because the maximum angle of rotation of the lever 24 connected over shaft 23 to the gear 22 and representing the driving element of the reduction gear is thus also under 360, The cam rigidly connected with the lever 24 describes a circular path 29. Above the latter the limit switches 26 are so arranged that they are actuated by the cam 25 and release impulses which start the measuresnecessary for controlling the individual units of the continuous machine. The limit switches 26 are arranged adjustably on the path line 29 for fine adjustment. Furthermore the lever 24 turns crank 27 rigidly connected with it on the correction element 28 which corrects the irregularities in the speeds between the lapping machine and the tufting mechanism in the normal operation of the continuous machine constantly or intermittently.

This correction element is, for example, a commercial potentiometer in an arrangement where a driving unit is driven with a thyristor-controlled d-c motor. In an arrangement where a driving unit can be varied in its speed over a mechanical infinitely variable speed gearing, the correction element consists, for example,

I of a combination of limit switches which transmits the control impulses to an adjusting motor connected to the variable speed gearing.

Since the correction elements are conventional elements, an exact graphic representation can be foreon conveyor means to a storage unit, withdrawing the fleece from said storage unit with a tufting machine, deriving a mechanical drive from a moving part of said conveyor means applying that drive as a first input to a two input differential gear, said first input beingproportional to the rate of delivery ofsaid fleece material, deriving a second mechanical drive from said tufting machine applying said second drive as a second input to said differential, said second input being proportional to the rate of withdrawal of said fleece material and deriving an output from said differential and applying said output to means for controlling one of said conveyor means and processing machines whereby one of the rates of'delivery and withdrawal is controlled proportionally to the difference in inputs to the differential to reduce the difference to zero.

2. The method as claimed in claim 1 wherein the rate of delivery is controlled.

3. The method of continuously producing a fleecelike fabric which comprises delivering a fleece material to a storage unit by means including a conveyor, withdrawing it from the storage unit by a tufting machine, deriving a mechanical drive from a moving part of said conveyor, applying that drive to a control device said drive being proportional to the rate at which the material is delivered to the storage unit and deriving a second mechanical drive from a moving part of said tufting machine, applying that second drive to said control device said second drive being proportional to the rate at which the material is withdrawn from said unit, deriving from said control device an output proportional to the differences in said drives and applying said output to control one of the delivery and withdrawal rates to maintain the contents of the storage unit substantially constant.

4. The method as claimed in claim 3 in which said drives are applied as inputs to a two input differential the case of which is stationary when the rates of delivery and withdrawal are equal.

5. Apparatus for the continuous production of a fleece-like fabric comprising a storage unit, a lapping machine delivering a fleece material to said storage unit, a tufting mechanism withdrawing the material from said storage unit, first drive means associated with the lapping machine and second drive means associated with the tufting mechanism, a differential having two input gears and a cage, means connecting a moving part of the lapping machine to drive one of said gears at a speed proportional to the rate of movement of said first drive means and means connecting a moving part of said tufting machine to drive the other of said gears at a speed proportional to the rate of movement of said second drive means, the case of said differential being stationary when the input gears are driven at the same speed and moving when said input gears are driven at different speeds and control means associated with one of said drive means, and means connecting said case to said control means, said control means being operable by said case as said case moves whereby the amount of fleece material in said storage unit is maintained substantially constant.

6. Apparatus as claimed in claim 5 wherein said differential case drives an operating member associated with limit switches for controlling said drive means.

7. Apparatus as claimed in claim 5 wherein said differential case drives an operating member associated with a speed control of said one drive means. 

1. The method of continuous production of a fleece-like fabric which comprises delivering a fleece material on conveyor means to a storage unit, withdrawing the fleece from said storage unit with a tufting machine, deriving a mechanical drive from a moving part of said conveyor means applying that drive as a first input to a two input differential gear, said first input being proportional to the rate of delivery of said fleece material, deriving a second mechanical drive from said tufting machine applying said second drive as a second input to said differential, said second input being proportional to the rate of withdrawal of said fleece material and deriving an output from said differential and applying said output to means for controlling one of said conveyor means and processing machines whereby one of the rates of delivery and withdrawal is controlled proportionally to the difference in inputs to the differential to reduce the difference to zero.
 2. The method as claimed in claim 1 wherein the rate of delivery is controlled.
 3. The method of continuously producing a fleece-like fabric which comprises delivering a fleece material to a storage unit by means including a conveyor, withdrawing it from the storage unit by a tufting machine, deriving a mechanical drive from a moving part of said conveyor, applying that drive to a control device said drive being proportional to the rate at which the material is delivered to the storage unit and deriving a second mechanical drive from a moving part of said tufting machine, applying that second drive to said control device said second drive being proportional to the rate at which the material is withdrawn from said unit, deriving from said control device an output proportional to the differences in said drives and applying said output to control one of the delivery and withdrawal rates to maintain the contents of the storage unit substantially constant.
 4. The method as claimed in claim 3 in which said drives are applied as inputs to a two input differential the case of which is stationary when the rates of delivery and withdrawal are equal.
 5. Apparatus for the continuous production of a fleece-like fabric comprising a storage unit, a lapping machine delivering a fleece material to said storage unit, a tufting mechanism withdrawing the material from said storage unit, first drive means associated with the lapping machine and second drive means associated with the tufting mechanism, a differential having two input gears and a cage, means connecting a moving part of the lapping machine to drive one of said gears at a speed proportional to the rate of movement of said first drive means and means connecting a moving part of said tufting machine to drive the other of said gears at a speed proportional to the rate of movement of said second drive means, the case of said differential being stationary when the input gears are driven at the same speed and moving when said input gears are driven at different speeds and control means associated with one of said drive means, and means connecting said case to said control means, said control means being operable by said case as said case moves whereby the amount of fleece material in said storage unit is maintained substantially constant.
 6. Apparatus as claimed in claim 5 wherein said differential case drives an operating member associated with limit switches for controlling said drive means.
 7. Apparatus as claimed in claim 5 wherein said differential case drives an operating member associated with a speed control of said one drive means. 